The Oracle vet has always been on the outside, raging against the machine of big software. But his web-based sales service is now fully in the mainstream. Everyone wants in on cloud software, and Salesforce stock has been on a tear, up 63% over the past year. And companies have been lapping up his new Chatter service, which adds a social layer to CRM. Further evidence of Benioff becoming The Man: This summer he announced that Salesforce would spend $278 million on land in San Francisco's Mission Bay to build a new headquarters.

Executives from Silicon Valley to Hollywood to Wall Street admires his savvy persistence - and his company's cool culture. The secret to the Netflix CEO's success? He never stops looking over his shoulder. More

Michael Dell was 21 when he first appeared in Fortune. Bill Gates made the cover when he was 30. Here's a look back at some of today's biggest business leaders when they were climbing the corporate ladder. More